There exist many scarfs, shawls, and capes, each having certain design, shapes, coloring, patterns, etc., to provide a given look or style to a person wearing such items. These items are typically single-purpose; as a scarf is not worn as a cape or a shawl, etc.
Closed garments typically have a fixed-sized opening of a certain size, for example, a head opening for a poncho. Having a fixed sized opening, such garments do not permit conversion between many different styles.
What is needed is a garment that is adjustable so that it can be worn as a cape, toga, cowl, shawl, etc.